Cycloalkene-1-mercaptoalkanoic acids, alkyl esters and metal salts



United States Patent Ofilice 3,3tlfi8d Patented Feb, 21 1967 3,305,580CYCLOALKENE-l-MERCAETUALKANOEC ACIDS, ALKYL ESTERS AND METAL SAL'E;

Otto A. Homhera, Woodlawn, and lingenuin Hechenhleikner and Edith H.Miller, Eincinnati, Ohio, assignors to Carlisle Chemical Works, The,Reading, Ohio, a corporation of Uhio l.

' N0 Drawing Fited Apr. 2, 1963, Ser. No. 269,863

13 Ciaims. (Cl. 260-468) The present invention relates to thepreparation of unsaturated sulfur containing carboXylic acids and to thepreparation of salts and esters of such acids.

The preparation of heterocyclic compounds by the reaction ofperhaloketones with thioacetic acid or thiopropionic acid is disclosedin Simmons Patent 2,911,414.

It is an object of the present invention to prepare sulfur containingunsaturated acids and esters and salts thereof which are devoid of aheterocyclic ring.

Another object is to prepare novel alkene and cycloalkene thio esters ofmercaptoalkanoic acids and the esters and salts thereof.

A further object is to improve the heat and light stability ofhalogen-containing resins.

An additional object is to provide novel stabilized vinyl resincompositions.

Yet another object is to provide novel synergistic stabilizers ofhalogen-containing resins.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter; it should be understood, however, that the detaileddescription and specific examples, while indicating preferred embodimentof the invention, are given by way of illustration only, since variouschanges and modifications within the spirit and scope of the inventionwill become apparent to those skilled in the art from this detaileddescription.

The novel compounds of the present invention have the formula R S(CH),,COOR where R is alkenyl, aralkenyl or cycloalkenyl in which thealiphatic or cycloaliphatic double bond is attached to the carbon atomdirectly attached to the sulfur atom and R is hydrogen, alkyl, ammoniumor a metal, e.g. sodium or potassium and n is an integer up to 10,preferably 1 or 2.

Examples of compounds within the invention arecyclohexene-l-rnercaptopropionic acid, cycloheXene-I-mercaptoaceticacid,

buytl cyclohexene-l-mercaptopropionate, hexylcyclohexene-l-mercaptopropionate, methyl cyclohexene-l-mercaptoacetate,methyl cyclohcxene-l-mercaptopropionate, octadecylcyclohexene-l-mercaptopropionate, octadecylcyclohexenel-mercaptoa-cetate, cyclohexene-l-mercaptobutyric acid,cyclohexene-l-mercaptodecanoic acid, sodiumcyclohexene-l-rnercaptoacetate, sodiumcyclohexene-l-rnercaptopropionate, ammoniumcyclohexene-l-mercaptopropionate, potassiumcyclohexene-l-mercaptoacetate, cyclopentene-l-mercaptopropionic acid,cyclopentene-l-mercaptoacetic acid,

butyl cyclopentene-l-mercaptoacetate, butylcyclopentene-l-mercaptopropionate, hexylcyclopentene-l-mercaptobutyrate, octylcyclopentene-l-mercaptopropionate, ethene-l-mercaptopropionic acid,ethene-1-mercaptoacetic acid,

amyl ethene-l-mercaptopropionate, propene-l-mercaptoacetic acid,propene-l-mercaptopropionic acid,

hexyl propene-lmercaptopropionate,

isodecene-l-mercaptopropionic acid, butyl S-Z-heptene mercaptoacetate,S-Z-heptene mercapt-opropionic acid, 2-thia-3-decenoic acid,3-thia-5-ethyl-4-heptenoic acid, 2-thia-4-ethyl-3-hexenoic acid,3-thia-4--undecenoic acid,

butyl 3-thia-4-undecenoate, 3-thia-4-eicosenoic acid,

methyl 3-thia-4-eicosenoate, propene-Z-mercaptoacetic acid,propene-Z-mercaptopropionic acid, heptyl propene-Z-mercaptoacetate,S-Z-butene mercaptopropionic acid, S-3-pentene mercaptoacetic acid,

butyl S-3-pentene mercaptopropionate, 4-phenyl-2-thia-3-butenoic acid,

S-methyl cyclohexene-larnercaptopropionic acid,l-phenylethene-l-mercaptopropionic acid.

The compounds of the present invention can be prepared by heating 1 moleof a mercaptoalkanoic acid with 1 mole, or preferably a slight excess of1 mole, of the appropriate aldehyde or ketone and removing 1 mole ofwater. The reaction is carried out in the presence of a water entrainersuch as a hydrocarbon solvent, e.g. toluene, benzene, xylene or naphthain the presence or absence of an acid catalyst such as hydrochloricacid, hydrobromic acid, p-toluenesulfonic acid, benzenesulfonic acid orsulfuric acid.

When mercaptoacetic acid is employed as a reactant there are foundsubstituted oxathiolanes as by-products. The desiredalkene-l-mercaptoacetic acid (or cycloalkenel-mercaptoacetic acid) canbe separated from the 1oxathiolane by adding dilute aqueous alkali suchas sodium bicarbonate, potassium bicarbonate or ammonium hydroxide. Thealkene-l-mercaptoacetic acid goes into the aqueous layer while theoxathiolane remain in the organic layer. The aqueous layer can beseparated and then evaporated to recover the salt of thealkene-l-mercaptoacetic acid or cycloalkene-l-inercaptoacetic acid.Alternatively the separated aqueous layer can be acidified, e.g. withhydrochloric acid to precipitate the alkene-lmercaptoacetic acid orcycloalkene-l-mercaptoacetic acid.

Since mercaptopropionic acid does not form cyclic compounds with thealdehydes and ketones there is no need to add aqueous alkali to thereaction product for separation purposes. However, aqueous alkali can beadded to form the salt of alkene or cycloalkene-1-mercaptopropionicacid. The salts thus are useful for forming the free alkene andcycloalkene-l-mercaptoalkanoic acids.

The alkene and cycloalkene mercaptopropionic acid compound can berecovered by distillation as can the alkylesters of alkene orcycloalkene mercaptopropionic (or mercaptoacetic) acids.

Distillation can also be employed to further purify the alkene orcycloalkene mercaptoacetic acids.

As starting aldehydes or ketones, there can be used acetaldehyde,propionaldehyde, butyraldehy-de, valeraldehyde, isovaleraldehyde,caprylaldehyde, Z-ethyl-butyraldehyde, stearaldehyde, phenylpropionaldehyde, acetone, methyl ethyl ketone, methyl propyl ketone,methyl butyl ketone, methyl isobutyl ketone, stearanone, diethyl ketone,dipropyl ketone, ethyl propyl ketone, acetophenone, propiophenone,cyclopentanone, cyclohexanone, Z-methyl cyclohexanone, methyl amylketone, and isodecaldehyde.

The compounds of the present invention, especially the free acids andthe alkyl esters are useful as stabilizers for halogen containingminerals particularly when used with tin compounds such as dialkyltinoxide and dialkyltin acylates.

The stabilizers of the present invention can be used with halogencontaining vinyl and vinylidene resins in which the halogen is attacheddirectly to the carbon atoms. Preferably, the resin is a vinyl halideresin, specifically, a vinyl chloride resin. Usually, the vinyl chlorideresin is made from monomers consisting of vinyl chloride alone or amixture of monomers comprising at least 70% vinyl chloride by weight.When vinyl chloride copolymers are stabilized, preferably the copolymerof vinyl chloride with an ethylenically unsaturated compoundcopolymerizahle therewith contains at least 10% of polymerized vinylchloride.

As the chlorinated resin there can be employed chlorinated polyethylenehaving 14 to 75%, e.-g., 27%, chlorine by weight. Polyvinyl chlorine,polyvinylidene chloride, polyvinyl bromide, polyvinyl fluoride,copolymers of vinyl chloride with 1 to 90%, preferably 1 to 30%, of acopolymerizable ethylenically unsaturated material such as vinylacetate, vinyl butyrate, vinyl benzoate, vinylidene chloride, diethylfumarate, diethyl maleate, other alkyl fumarates and maleates, vinylpropionate, methyl acrylate, Z-ethylhexyl acrylate, butyl acrylate andother alkyl acrylates, methyl methacrylate, ethyl methacrylate, butylmethcrylate and other alkyl methacrylates, methyl alpha chloroacrylate,styrene, trichloroethyiene, vinyl ethers such as vinyl ethyl ether,vinyl chloroethyl ether and vinyl phenyl ether, vinyl ketones such asvinyl methyl ketone and vinyl phenyl ketone, l-luoro-l-chl oroethylene,acrylonitrile, chloroacrylonitrile, allylidene di acetate andchloroallylidene diacetate. Typical copolymers include vinylchloride-vinyl acetate (96:4 sold commercially as VYNW), vinylchloride-vinylac-etate (87:13), vinyl chloride-vinyl aceta-te-maleicanhydride (86:13: 1), vinyl chloride-vinylidene chloride (95:5), vinylchloride-diethyl fumarate (95:5), vinyl chloride trichloroethylene(95:5), vinyl chloride-2-ethylhexyl acrylate (80:20).

The stabilizers of the present invention can be incorporated with theresin by admixing in an appropriate mill or mixer or by any of the otherWell-known methods which provide for uniform distribution throughout theresin compositions. Thus, mixing can be accomplished by milling on rollsat 100-160 C.

In addition to the novel stabilizers there can also be incorporated withthe resin conventional additives such as plasticizers, pigments,fillers, dyes, ultraviolet light absorbing agents, densifying agents andthe like.

If a plasticizer is employed, it is used in conventional amount, e.g.,30 to 150 parts per 100 parts of resin.

Typical plasticizers are di-Z-ethyl-hexyl phthalate, dibutyl sebacate,dioctyl sebaoate, .tricresyl phosphate.

Examples of suitable tin compounds for use as stabilizers with thecompounds of the present invention are dibutyltin oxide, dibutyltindilaurate, dioctyltin oxide, dioctyltin dilaurate.

The compounds of the present invention are normally used in an amount of0.01 to 10% by weight of the resin.

The tin compounds are also normally used in an amount of 0.01 to 10% byweight of the resin. More preferably 0.2 to of the tin compound and 0.2to 5% of the alkene or cycloalkene mercaptoalkanoic acid (or 'alkylester thereof) of the present invention are used based on the weight ofthe resin.

Unless otherwise indicated all parts and percentages are by weight.

The alkene and cycloalkene group containing compounds of the presentinvention can also be prepared by forming a thioacetal or thioketal from2 moles of meroaptoacetic acid or mercaptopropionic acid or an alkylester thereof and 1 mole of the appropriate aldehyde or ketone and thenheating to remove 1 mole of mercaptoacetic acid.

Example 1 1 mole of merca ptopropionic acid and 1.1 mole ofcyclohexanone were refluxed in toluene with removal of water (thereactants together equalled by Weight of the total mixture) until 18grams of Water were obtained. The product Was then distilled andcyclohexene- I-rnercaptopropionic acid was recovered as a yell-ow liquidhaving an 11 15319 and a B.P. of 142-145" C. at 0.5 mm. Hg. The producthad the formula Example 2 The procedure of Example 1 was repeatedreplacing the mercaptopropionic acid by 1 mole of butylmercaptopropionate. The product was butylcycloheXene-l-mercaptopropionate, a colorless liquid having an n l.4983,having a B.P. of 133 C. at 0.5 mm. Hg and having the formula i qmorno'10 o o n-n Example 3 The procedure of Example 1 was repeated replacingthe mercaptopropionic acid by 1 mole of butyl mercaptoacetate. Theproduct was butyl cyclohexene-l-mercaptoacetate, a. colorless liquidhaving an 11 of 1.5022 and having a B.P. of 133-140 C. at 1.9 mm. Hg.

Example 4 The procedure of Example 1 was repeated but the reactantsemployed were 1 mole of butyl mercaptoacetatc and 1.1 mole of methylamyl ketone. The product was butyl S-Z-heptene mercaptoacetate, acolorless liquid having an M 1.4739, a HP of 1l7126 C., at 0.3 mm. andhaving the formula Example 5 Example 6 The procedure of Example 1 wasrepeated replacing the cyclohexanone by 1.1 mole of isodecaldehyde. Theproduct Was isodecene-l-mercaptopropionic acid, a colorless liquidhaving an 11 1.4878, a. B.P. of l63l73 C., at 0.4 mm. and having theformula The procedure of Example 5 was repeated replacing thecyclopentanone by 1.1 mole of methyl amyl ketonc. The product wasS-Z-heptene mercaptopropionic acid, a light brown solid melting at about37 C. and having the formula CH3C=CH(CH1);CH3

SCHlCHflCOOII Example 8 1 mole of mercaptoacetic acid and 1.1 mole ofcaprylaldehyde were refluxed in toluene with removal of water until 18grams of water were obtained. The reactants together equalled 80% byweight of the total mixture. The product was then treated with an equalweight of dilute aqueous sodium bicarbonate and the water layercontaining the sodium salt of 2-thia-3-decenoic acid separated from theorganic layer. The water layer was then neutralized with hydrochloricacid to separate the free 2-thia-3-decenoic acid, from the water. Afterre moval of the aqueous layer the 2-thia-3-decenoic acid having theformula CH (CH CH=CHSCH COOH was recovered as a colorless liquid havingan 11 1.4919 and a boiling point of 130-138 C. at 0.5 mm. Hg.

Example 9 The procedure of Example 1 Was repeated replacing thecyclohexanone by 1.1 mole of Z-ethylbutyraldehyde. The product was3-thia-5-ethyl-4-heptenoic acid, a deep yellow liquid having an 12,1.5015, a B.P. of 132-138 C. at 0.3 mm. and the formula CgIIsCHzCH2C=CHSCH2CH2C O OH Example 10 The procedure of Example 1 wasrepeated using as the reactants 1 mole of rnercaptoacetic acid and 1.1mole of 2ethylbutyraldehyde. The product was 2-thia-4-ethyl-3- hexenoicacid, a colorles liquid having an n 1.5008 an-d a B.P.of130-140 C. at 2mm. Hg.

Example 11 The procedure of Example 5 was followed replacing thecyclopentanone by 1.1 mole of caprylaldehyde. The product was3-thia-4-undecenoic acid, a yellow liquid having 11 1.4898 and a B.P. ofl47150 C. at 0.3 mm. Hg.

Example 12 The procedure of Example 1 was followed employing as thereactants 1 mole of butyl mercaptopropionate and 1.1 mole ofcaprylaldehyde. The product was ibutyl 3-tbia-4-undecenoate, a paleyellow liquid having an 21 1.4731 and a B.P. of 136-146 C. at 1 mm. Hg.

Example 13 100 parts of Geon 101EP (vinyl chloride homopolymer) wasmixed with 0.37 part dibutyltin oxide and 0.30 part ofcyclohexane-l-mercaptopropionic acid to form a heat stable product.

Example 14 Example 13 was repeated but 50 parts of dioctyl phthalate wasincluded in the composition. The product was heat stable.

What is claimed is:

11. A compound having the formula R S(CH ),,COOR where R is cycloalkenylin which the double bond is on the carbon atom adjacent to the suifuratom, R is selected from the group consisting of hydrogen, alkyl and ametal and n is an integer of at le-ast 1.

2. A compound according to claim 1 wherein R is lower alkyl.

3. Cycloalkene-l-mercaptoalkanoic acids wherein the cycl-oalkene grouphas 5 to 6 carbon atoms and the mercaptoalkanoic group has 2 to 3 carbonatoms.

4. Cyclohexene-1-mercaptoalkanoic acids wherein the mercaptoalkanoicgroup has 2 to 3 carbon atoms.

5. Cyclohexeue-l-rnercaptoacetic acid.

6. Cyclohexene-1-mercaptopropionic acid.

'7. Cyclopentene-l-rnercaptoalkanoic acids wherein the mercaptoalkanoicgroup has 2 to 3 carbon atoms.

8. Alkyl esters of cycloalkene-l-mercaptoalkanoic acids wherein thecycloalkene group has 5 to 6 carbon atoms and the .meroaptoalkanoicgroup has 2 to 3 carbon atoms wherein the alkyl group has 1 to 18 carbonatoms.

9. A compound according to claim 8 Where the alkyl is lower alkyl.

10. Alkyl esters of cyclohexene-l-mercaptoalkanoic acids wherein themercaptoalkanoic group has 2 to 3 carbon atoms wherein the alkyl grouphas 1 to 18 carbon atoms.

11. A compound according to claim 10 is lower alkyl.

12. Alkyl esters of cyclohexene-l-mercaptopropionic acid wherein thealkyl group has 1 to 18 carbon atoms.

13. A compound according to claim 12 where the alkyl is lower alkyl.

where the alkyl References Cited by the Examiner UNITED STATES PATENTS3,026,349 3/1962 Celrner 260516 X FOREIGN PATENTS 839,561 6/1960 GreatBritain.

OTHER REFERENCES vol. 61 1939 LORRAINE A. WEINBERGER, Primary Examiner.R. K. JACKSON, Assistant Examiner.

1. A COMPOUND HAVING THE FORMULA R1S(CH2)NCOOR2 WHERE R1 IS CYCLOALKENYLIN WHICH THE DOUBLE BOND IS ON THE CARBON ATOM ADJACENT TO THE SULFERATOM, R2 IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ALKYL AND AMETAL AND N IS AN INTEGER OF AT LEAST 1.